Small business rate relief - how much longer?

[The Don of Croy]

I am happy to be occupying a unit that enjoys the 100% rate relief (one of chancellor Osbourne's last acts?) so saving my business about £4k per year (and very handy given current parlous state of trade).

Does anyone know when this 'relief' will end? Other than 30 secs after Chancellor McDonnell stands up to give his first budget...

As an aside, we still receive junk emails on a daily basis demanding that we 'act now! to reduce our rateable value' from various charlatans spamming everyone. Be nice if they could save me more money.